CN107754859B

CN107754859B - Catalyst and its preparation method and application

Info

Publication number: CN107754859B
Application number: CN201710893400.3A
Authority: CN
Inventors: 吴彦霞; 赵春林; 梁海龙; 陈鑫; 唐婕; 胡利明
Original assignee: China Building Materials Academy CBMA
Current assignee: China Building Materials Academy CBMA
Priority date: 2017-09-27
Filing date: 2017-09-27
Publication date: 2019-09-10
Anticipated expiration: 2037-09-27
Also published as: CN107754859A

Abstract

The present invention relates to a kind of catalyst and its preparation method and application, wherein catalyst includes carrier and active component, wherein the carrier includes MIL-101, the active component includes Fe³⁺、Fe²⁺、Cu²⁺.Preparation method includes, the carrier is placed in the mixed solution of molysite and mantoquita, reaction, the product that reaction obtains is dried, is roasted to get the catalyst is arrived, wherein, the molysite is the mixture of trivalent iron salt and divalent iron salt, mantoquita is cupric salt, and in the mixed solution, the mass fraction of divalent, trivalent iron salt and cupric salt mixture is 2-5%.The present invention provides it is a kind of it is reusable, high catalytic efficiency, can large-scale application new catalyst, especially there is very high degradation effect to the organic phenolic compound in waste water.

Description

Catalyst, preparation method and application thereof

Technical Field

The invention relates to preparation and application of a heterogeneous Fenton catalyst in the technical field of phenol-containing wastewater treatment, in particular to a preparation method and application of a bimetallic Fe-Cu supported metal organic framework type Fenton catalyst.

Background

In the production process of chemical industry, pharmacy, petroleum and other industries, various harmful substances with potential toxicity such as carcinogenesis and teratogenesis can be generated, and the substances not only pollute air, soil and water, but also seriously harm human beings and other organisms. Industrial waste water containing phenols is one of the important water pollutants. The existing technologies for eliminating such organic wastewater include biodegradation, activated carbon adsorption, photocatalytic degradation and electrochemical oxidation, but these methods are not widely used in industry due to the limitations of wastewater concentration, volume and operation cost.

Advanced oxidation technologies (AOPs) using strongly oxidizing radicals (mainly. OH) as an oxidizing agent have a remarkable effect of treating phenolic wastewater, and have recently been drawing attention from researchers. The Fenton oxidation technology is one of the main methods in the advanced oxidation technology, and mainly utilizes H₂O₂The reaction with Fe (II)/Fe (III) ions to generate OH free radicals with strong oxidizability to achieve the purpose of oxidatively decomposing organic matters has the advantages of mild reaction conditions (normal pressure and room temperature), easy operation, easy obtaining of reactants, no need of complex equipment, low cost and the like, so the method is considered to be the most economical choice for treating organic wastewater. However, the traditional Fenton system has some disadvantages, such as narrow applicable pH value, generation of iron mud in the reaction process to cause secondary pollution, and further separation and treatment.

In recent years, Fe²⁺The heterogeneous Fenton system immobilized by the metal ions has good catalytic oxidation efficiency and can effectively overcome the defects of the homogeneous system, so that the heterogeneous Fenton reaction process is as follows:

S-Fe²⁺+H₂O₂→S-Fe³⁺+OH^-+HO· (1)

S-Fe³⁺+H₂O₂→S-Fe²⁺+HO₂·+H⁺ (2)

wherein S represents the surface of the catalyst.

Among them, iron-copper bimetallic heterogeneous Fenton catalyst systems are receiving more and more attention. It has been reported that an iron-copper bimetallic catalyst supported on an MCM-41 molecular sieve shows higher catalytic activity than a Cu or Fe monometallic supported catalyst; MIL-101 is a novel MOFs material synthesized and reported by the Ferey organization of France.

Disclosure of Invention

The invention mainly aims to provide a catalyst, a preparation method and application thereof, and aims to solve the technical problem of providing a novel catalyst which can be repeatedly used, has high catalytic efficiency and can be applied in a large scale, so that the novel catalyst is more practical.

The purpose of the invention and the technical problem to be solved are realized by adopting the following technical scheme.

The catalyst provided by the invention comprises a carrier and an active component, wherein the carrier comprises MIL-101, and the active component comprises Fe³⁺、Fe²⁺、Cu²⁺。

The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, the catalyst further comprises a carrier which is MIL-101 (Cr).

The object of the present invention and the technical problem to be solved are also achieved by the following technical means.

According to the preparation method of the catalyst provided by the invention, the preparation method of the catalyst comprises the steps of placing the carrier in a mixed solution of ferric salt and cupric salt, reacting, drying and roasting a product obtained by the reaction to obtain the catalyst, wherein the ferric salt is a mixture of ferric salt and ferrous salt, the cupric salt is cupric salt, and the mass fraction of the mixture of the ferrous salt, the ferric salt and the cupric salt in the mixed solution is 2-5%. The term "mixture of divalent and trivalent iron salts and divalent copper salts" as used herein refers to a mixture of divalent iron salt compounds, trivalent iron salt compounds and divalent copper salt compounds, and the sum of the mass of these three compounds is 2-5% of the mass of the solution. The mixture of the divalent iron salt, the trivalent iron salt and the divalent copper salt in the mixed solution is defined as a solute component, and the mass ratio of the carrier to the solute component is 5: 0.2-0.5. The object of the present invention and the technical problems solved thereby can be further achieved by the following technical measures.

Preferably, in the method for preparing a catalyst, the molar ratio of the iron ions to the copper ions in the mixed solution is 2:1 to 6:1, and it should be noted that the iron ions herein include ferric ions and ferrous ions.

Preferably, in the above method for preparing a catalyst, the mixed solution contains Fe²⁺With Fe³⁺The molar ratio of (A) to (B) is 9:1-15: 1.

Preferably, the method for preparing the catalyst is that the ferrous salt is FeSO₄·7H₂O, the ferric salt is FeCl₃·6H₂O and/or Fe (NO)₃)₃·9H₂O; or the copper salt is CuSO₄·5H₂O、CuCl₂Or Cu (NO)₃)₂·3H₂And one or more of O.

Preferably, in the preparation method of the catalyst, the reaction is carried out under the water bath condition, the temperature of the water bath condition is 60-80 ℃, and the reaction time is 3-6 h; or, the drying is carried out under vacuum condition, the drying temperature is 105 ℃, and the drying time is 4 h; or, the roasting is carried out in the nitrogen atmosphere, the roasting temperature is 250-300 ℃, and the roasting time is 2-5 h.

According to the application of the catalyst provided by the invention, the catalyst is used for treating wastewater, and the wastewater contains organic phenolic compounds.

Preferably, in the application of the catalyst, the catalyst and hydrogen peroxide are put into wastewater to perform wastewater treatment, wherein the concentration of the organic phenolic compounds in the wastewater is 100-1000 mg/L; or the input amount of the catalyst is 0.1-1.5 g/L; or the input amount of the hydrogen peroxide is 2-50 mmol/L.

Preferably, the use of one of the aforementioned catalysts, wherein the temperature of the wastewater treatment is 20 to 30 ℃; the pH value of the wastewater is 3-5; the time for treating the wastewater is 10-60 min.

By the technical scheme, the catalyst, the preparation method and the application thereof provided by the invention at least have the following advantages:

1. the invention provides a novel catalyst.

The invention takes MIL-101 (preferably MIL-101(Cr)) as a carrier, and a Fe-Cu bimetal is loaded on the carrier to prepare the novel catalyst. The novel catalyst provided by the invention has the advantages of uniform and ordered carrier pore channels, high catalytic activity, good stability, wide pH range in use and the like.

The traditional Fenton-like reagent only loads Fe ions, and the invention addsCu²⁺。Cu²⁺Mainly by with HO₂·/O₂·^-Reaction to form Cu⁺，Cu⁺On the one hand can be mixed with H₂O₂OH is formed by the reaction, and Fe is reacted³⁺Reduction to Fe²⁺The production efficiency of OH is improved. Meanwhile, the carrier has a larger specific surface area, so that the contact area of metal ions and waste liquid is increased, and the catalytic efficiency is further improved.

The catalyst provided by the invention simultaneously comprises iron ions and copper ions, and the two ions interact with each other, so that the catalytic stability of active components in the catalyst is improved, and the application range of the catalyst is further enlarged. The catalyst provided by the invention can stably play a catalytic role under acidic or neutral conditions.

2. The catalyst provided by the invention has high degradation rate and degradation efficiency on organic phenolic compounds.

The degradation rate of the catalyst on the organic phenolic compounds is over 90 percent, and the degradation can be completed in a short time (the reaction time is less than or equal to 60 min).

3. The invention provides a preparation method of a catalyst. The method has simple process and low cost, and is suitable for large-scale industrial production.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

FIG. 1 is a scanning electron micrograph of a catalyst prepared according to an example of the present invention.

FIG. 2 shows the number of cycles of phenol treatment using the catalyst prepared in the example of the present invention.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description of a catalyst, its preparation method and its application, specific embodiments, structures, characteristics and effects thereof according to the present invention will be made with reference to the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "an embodiment" refers to not necessarily the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The invention provides a novel catalyst.

The catalyst provided by the invention comprises a carrier and an active component, wherein the carrier comprises MIL-101, and the active component comprises Fe³⁺、Fe²⁺、Cu²⁺. Preferably, the carrier is MIL-101(Cr), and a bimetallic Fe-Cu supported metal organic framework Fenton catalyst is obtained.

The carrier of the catalyst provided by the invention is MIL-101, and more preferably MIL-101(Cr), and the carrier has very large specific surface area and pore volume, and the specific surface area is generally 900-1500 m²The pore volume is 1-3 cm³(ii) in terms of/g. In addition, the active components of the catalyst are uniformly dispersed, and the catalytic capability is strong; wherein the active component contains Fe³⁺、Fe²⁺、Cu²⁺. The circulation between the ferrous iron and the ferric iron loaded on the carrier effectively promotes the decomposition capability of the catalyst on the hydrogen peroxide, accelerates the generation rate of hydroxyl free radicals, and thus effectively enhances the catalytic activity of the catalyst. Cu²⁺Without significant catalytic decomposition of H by itself₂O₂Ability to degrade organic matter, but will be against Fe²⁺/H₂O₂And Fe³⁺/H₂O₂The oxidized organic matter of the system shows obvious promotion effect.

The invention further provides a preparation method of the catalyst, which comprises the following steps:

(1) mixing Cr (NO) in a polyvinyl chloride autoclave₃)₃·9H₂O (800mg), terephthalic acid (332mg), hydrofluoric acid (40 wt%, 0.2mL) and deionized water (9.5mL) and held at 220 ℃ for 8 hours. Washing the synthesized MIL-101(Cr) with hot DMF (60-80 ℃, 3-5 h, 2-3 times) to remove unreacted terephthalic acid. And then washing the product in hot ethanol (60-80 ℃, 3-5 h, 2-3 times) to replace DMF molecules in the pores. And drying the solid product at 60-80 ℃ for 2-5h, and finally, drying at 150 ℃ in vacuum overnight to obtain the metal-organic framework MIL-101(Cr) carrier.

(2) And (2) taking 5g of the MIL-101(Cr) prepared in the step of preparing the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst, putting the MIL-101(Cr) into 10ml of mixed solution of iron salt and copper salt with the mass fraction of 2-5%, reacting in a constant-temperature water bath at the temperature of 60-80 ℃ for 3-6h, drying in vacuum at the temperature of 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at the temperature of 250-300 ℃ for 2-5 h.

The invention further defines that in the preparation process of the catalyst, the ferric salt is a mixture of ferric salt and ferrous salt, the copper salt is cupric salt, and the mass fraction of the active component in the mixed solution is 2-5%. In the mixed solution, the molar ratio of iron ions to copper ions is 2:1-6: 1. In the mixed solution, Fe²⁺With Fe³⁺The molar ratio of (A) to (B) is 9:1-15: 1. The circulation between the ferrous iron and the ferric iron loaded on the carrier effectively promotes the decomposition capability of the catalyst on the hydrogen peroxide, accelerates the generation rate of hydroxyl free radicals, and thus effectively enhances the catalytic activity of the catalyst. Cu²⁺Without significant catalytic decomposition of H by itself₂O₂Ability to degrade organic matter, but will be against Fe²⁺/H₂O₂And Fe³⁺/H₂O₂The oxidized organic matter of the system shows obvious promotion effect.

In the catalyst provided by the invention, Fe with catalytic activity³⁺、Fe²⁺、Cu²⁺The catalyst is required to be stably loaded on a carrier, and the mass percentage of the three active components is strictly controlled to exert higher catalytic efficiency. Furthermore, drying under vacuum condition and roasting in nitrogen atmosphere are favorable for preventing metal ions from being oxidized by oxygen in the air to change the valence state, and are favorable for controlling the content of each ion of active components in the catalyst, improving the stability of the catalyst and improving the catalytic efficiency.

Example 1

(1) Mixing Cr (NO) in a polyvinyl chloride autoclave₃)₃·9H₂O (800mg), terephthalic acid (332mg), hydrofluoric acid (40 wt%, 0.2mL) and deionized water (9.5mL) and held at 220 ℃ for 8 hours. The synthesized MIL-101(Cr) was washed with hot DMF (60 ℃, 5h, 3 times) to remove unreacted terephthalic acid. The product was then washed in hot ethanol (60 ℃, 5h, 3 times) to displace the DMF molecules in the wells. Drying the solid product at 60 ℃ for 5h, and finally drying at 150 ℃ overnight under vacuum to obtain the metal-organic framework MIL-101(Cr) carrier.

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 2%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 18: 2: 5.

(3) Adding 0.5g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L hydrogen peroxide into 100mg/L phenol solution, adjusting the pH value to 3, and reacting for 30 min. The effect of removing phenol is obvious, and the phenol degradation rate reaches more than 99 percent. After the catalyst provided by the embodiment is subjected to catalytic reaction for 30min, the degradation rate of phenol can reach 99%, and the catalyst provided by the invention has high degradation efficiency on phenol.

FIG. 1 is a scanning electron micrograph of the catalyst prepared in this example.

Fig. 2 shows that the catalyst prepared in this example is repeatedly used for degrading phenol, and the result shows that the degradation rate of phenol can still reach 90% after the catalyst is recycled for 12 times (the degradation rates in fig. 2 are detected after reaction for 30 min). The catalyst prepared by the invention can be recycled, and the use frequency is more than 12 times.

The structural parameters of the catalyst prepared in this example are shown in Table 1, and the degradation rate of phenol is shown in Table 2.

Example 2

(1) Mixing Cr (NO) in a polyvinyl chloride autoclave₃)₃·9H₂O (800mg), terephthalic acid (332mg), hydrofluoric acid (40 wt%, 0.2mL) and deionized water (9.5mL) and held at 200 ℃ for 10 hours. The synthesized MIL-101(Cr) was washed with hot DMF (75 ℃ C., 3h, 3 times) to remove unreacted terephthalic acid. The product was then washed in hot ethanol (75 ℃, 3h, 3 times) to displace the DMF molecules in the wells. Drying the solid product at 80 ℃ for 3h, and finally drying at 150 ℃ overnight under vacuum to obtain the metal-organic framework MIL-101(Cr) carrier.

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 3%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuCl₂Reacting in the mixed solution in a constant-temperature water bath at 75 ℃ for 5h, then drying in vacuum at 105 ℃ for 5h, and finally roasting in a nitrogen atmosphere at 280 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 12: 1: 5.

(3) Adding 1g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 30mmol/L hydrogen peroxide into 500mg/L phenol solution, adjusting the pH value to 4, and reacting for 40 min. The effect of removing phenol is obvious, and the phenol degradation rate reaches more than 90 percent.

Example 3

(1) Mixing Cr (NO) in a polyvinyl chloride autoclave₃)₃·9H₂O (800mg), terephthalic acid (332mg), hydrofluoric acid (40 wt%, 0.2mL) and deionized water (9.5mL) and held at 220 ℃ for 8 hours. The synthesized MIL-101(Cr) was washed with hot DMF (80 ℃, 3h, 3 times) to remove unreacted terephthalic acid. The product was then washed in hot ethanol (80 ℃, 3h, 3 times) to displace the DMF molecules in the wells. Drying the solid product at 80 ℃ for 3h, and finally drying at 150 ℃ overnight under vacuum to obtain the metal-organic framework MIL-101(Cr) carrier.

(2) Taking 5g of MIL-101(Cr) prepared above, and placing 10m of FeSO 1 with mass fraction of 5%₄·7H₂O、Fe(NO₃)₃·9H₂O、Cu(NO₃)₂·3H₂Reacting in an O mixed solution in a constant-temperature water bath at 80 ℃ for 3h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 300 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 15: 1: 3.

(3) Adding 1.5g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 50mmol/L hydrogen peroxide into 1000mg/L phenol solution, adjusting the pH value to 5, and reacting for 60 min. The effect of removing phenol is obvious, and the phenol degradation rate reaches more than 93 percent.

Example 4

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 2%₄·7H₂O、FeCl₃·6H₂O、Cu(NO₃)₂·3H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 18: 2: 5.

(3) Adding 0.5g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L hydrogen peroxide into 100mg/L phenol solution, adjusting the pH value to 3, and reacting for 30 min. The effect of removing phenol is obvious, and the phenol degradation rate reaches more than 95 percent.

Example 5

(1) Mixing Cr (NO) in a polyvinyl chloride autoclave₃)₃·9H₂O (800mg), terephthalic acid (332mg), hydrofluoric acid (40 wt%, 0.2mL) and deionizationWater (9.5mL) was added and maintained at 200 ℃ for 10 hours. The synthesized MIL-101(Cr) was washed with hot DMF (75 ℃ C., 3h, 3 times) to remove unreacted terephthalic acid. The product was then washed in hot ethanol (75 ℃, 3h, 3 times) to displace the DMF molecules in the wells. Drying the solid product at 80 ℃ for 3h, and finally drying at 150 ℃ overnight under vacuum to obtain the metal-organic framework MIL-101(Cr) carrier.

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 3%₄·7H₂O、FeCl₃·6H₂O、CuCl₂Reacting in the mixed solution in a constant-temperature water bath at 75 ℃ for 5h, then drying in vacuum at 105 ℃ for 5h, and finally roasting in a nitrogen atmosphere at 280 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 12: 1: 5.

(3) Adding 1g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 30mmol/L hydrogen peroxide into 500mg/L phenol solution, adjusting the pH value to 4, and reacting for 40 min. The effect of removing phenol is obvious, and the phenol degradation rate reaches more than 92 percent.

Example 6

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 5%₄·7H₂O、FeCl₃·6H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 80 ℃ for 3h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 300 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 15: 1: 3.

(3) Adding 1.5g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 50mmol/L hydrogen peroxide into 1000mg/L phenol solution, adjusting the pH value to 5, and reacting for 60 min. The effect of removing phenol is obvious, and the phenol degradation rate reaches more than 91 percent.

Comparative example 1

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 1%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 18: 2: 5.

(3) Adding 0.5g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L hydrogen peroxide into 100mg/L phenol solution, adjusting the pH value to 3, and reacting for 30 min. The degradation rate of phenol was 80%.

Comparative example 2

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 6%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 18: 2: 5.

(3) Adding 0.5g/L bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L hydrogen peroxide into 100mg/L phenol solution, adjusting the pH value to 3, and reacting for 30 min. The degradation rate of phenol was 81%.

Comparative example 3

(1) Mixing Cr (NO) in a polyvinyl chloride autoclave₃)₃·9H₂O (800mg), terephthalic acid (332mg), hydrofluoric acid (40 wt%, 0.2mL) and deionized water (9.5mL) and held at 220 ℃ for 8 hours. The synthesized MIL-101(Cr) was washed with hot DMF (60 ℃, 5h, 3 times) to remove unreacted terephthalic acid. Then theThe product was washed in hot ethanol (60 ℃, 5h, 3 times) to displace the DMF molecules in the wells. Drying the solid product at 60 ℃ for 5h, and finally drying at 150 ℃ overnight under vacuum to obtain the metal-organic framework MIL-101(Cr) carrier.

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 2%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 24: 4: 7.

(3) ① adding 0.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 84%, ② adding 1.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 87%, ③ adding 2.0g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, and reacting for 30min, wherein the degradation rate of phenol is 89%.

Comparative example 4

(2) Taking 5g of MIL-101(Cr) prepared above, placing in10ml of FeSO with the mass fraction of 2%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 80: 4: 21.

(3) ① adding 0.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 88%, ② adding 1.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 86%, ③ adding 2.0g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, and reacting for 30min, wherein the degradation rate of phenol is 87%.

Comparative example 5

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 2%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare heterogeneous Fe-Cu/MIL-A 101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 9: 1: 10.

(3) ① adding 0.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 79%, ② adding 1.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 82%, ③ adding 2.0g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, and reacting for 30min, wherein the degradation rate of phenol is 83%.

Comparative example 6

(2) Taking 5g of MIL-101(Cr) prepared above, and placing in 10ml of FeSO with mass fraction of 2%₄·7H₂O、Fe(NO₃)₃·9H₂O、CuSO₄·5H₂Reacting in an O mixed solution in a constant-temperature water bath at 60 ℃ for 6h, then drying in vacuum at 105 ℃ for 4h, and finally roasting in a nitrogen atmosphere at 250 ℃ for 3h to prepare the heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst. Wherein, Fe²⁺∶Fe³⁺∶Cu²⁺(molar ratio) 36: 4: 5.

(3) ① adding 0.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 77%, ② adding 1.5g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, reacting for 30min, wherein the degradation rate of phenol is 80%, ③ adding 2.0g/L of bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton catalyst and 5mmol/L of hydrogen peroxide into 100mg/L of phenol solution, adjusting the pH to 3, and reacting for 30min, wherein the degradation rate of phenol is 82%.

Table 1 shows the structural parameters of the bimetallic heterogeneous Fe-Cu/MIL-101(Cr) Fenton-type catalysts of examples 1-6

Examples	Specific surface area (m)²/g)	Pore size (nm)	Pore volume (cm)³/g)
				Example 1	1394.9	0.623	2.28
Example 2	1056.4	0.527	2.13
				Example 3	973.6	0.797	2.09
Example 4	1215.3	0.641	2.18
				Example 5	1132.4	0.577	2.04
Example 6	1036.2	0.682	1.98

Table 2 shows the phenol degradation rates of the Fenton-like reaction systems of examples 1 to 6

The recitation of numerical ranges herein includes all numbers subsumed within that range and includes any two numbers subsumed within that range. For example, "a mass fraction of 2-5%", where the range of values includes all values between 2-5, and includes any two values (e.g., 3, 4) within the range as a combined range of values (3-4); different values of the same index appearing in all embodiments of the invention can be combined arbitrarily to form a range value.

The features of the invention claimed and/or described in the specification may be combined, and are not limited to the combinations set forth in the claims by the recitations therein. The technical solutions obtained by combining the technical features in the claims and/or the specification also belong to the scope of the present invention.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A catalyst, characterized by:

the catalyst comprises a carrier and an active component, wherein the carrier comprises MIL-101, and the active component comprises Fe³⁺、Fe²⁺、Cu²⁺；

The preparation method of the catalyst comprises the following steps:

placing the carrier in a mixed solution of iron salt and copper salt, reacting, and drying and roasting a product obtained by the reaction to obtain the catalyst;

wherein in the mixed solution, the mass fraction of the mixture of divalent and trivalent iron salts and divalent copper salt is 2-5%, and Fe² ⁺With Fe³⁺The molar ratio of the iron ions to the copper ions is between 2:1 and 6:1, and the molar ratio of the iron ions to the copper ions is between 9:1 and 15: 1.

2. A catalyst according to claim 1, wherein:

the carrier is MIL-101 (Cr).

3. A method for preparing a catalyst, which is characterized by comprising the following steps:

the catalyst according to any one of claims 1 or 2, which is prepared by a method comprising,

putting the carrier into a mixed solution of ferric salt and cupric salt, reacting, drying and roasting a product obtained by the reaction to obtain the catalyst,

wherein the ferric salt is a mixture of ferric salt and ferrous salt, the copper salt is cupric salt, and the mass fraction of the mixture of the ferrous salt, the ferric salt and the cupric salt in the mixed solution is 2-5%;

in the mixed solution, the molar ratio of iron ions to copper ions is 2:1-6:1, and Fe²⁺With Fe³⁺The molar ratio of (A) to (B) is 9:1-15: 1.

4. A method of preparing a catalyst according to claim 3, wherein:

the ferrous salt is FeSO₄·7H₂O, the ferric salt is FeCl₃·6H₂O and/or Fe (NO)₃)₃·9H₂O; or,

the copper salt is CuSO₄·5H₂O、CuCl₂Or Cu (NO)₃)₂·3H₂And one or more of O.

5. A method of preparing a catalyst according to claim 3, wherein:

the reaction is carried out under the condition of water bath, the temperature of the water bath is 60-80 ℃, and the reaction time is 3-6 h; or,

the drying is carried out under a vacuum condition, the drying temperature is 105 ℃, and the drying time is 4 hours; or,

the roasting is carried out in a nitrogen atmosphere, the roasting temperature is 250-300 ℃, and the roasting time is 2-5 h.

6. Use of a catalyst, characterized in that:

the catalyst according to any one of claims 1 or 2, which is used for wastewater treatment containing organic phenolic compounds.

7. Use of a catalyst according to claim 6, wherein:

the catalyst and hydrogen peroxide are put into wastewater for wastewater treatment, wherein,

the concentration of the organic phenolic compounds in the wastewater is 100-1000 mg/L; or,

the input amount of the catalyst is 0.1-1.5 g/L; or,

the input amount of the hydrogen peroxide is 2-50 mmol/L.

8. Use of a catalyst according to claim 7, wherein:

the temperature of the wastewater treatment is 20-30 ℃;

the pH value of the wastewater is 3-5;

the time for treating the wastewater is 10-60 min.